# well-formed BCP 47 syntax, but not "valid" per RFC 5646 §2.2.9 / §4.1
# because a variant or extension singleton subtag is repeated

# duplicate variant subtag
de-DE-1901-1901

# duplicate variant subtag, case-insensitive match
en-rozaj-ROZAJ

# duplicate extension singleton subtag
en-a-foo-a-bar

# duplicate extension singleton subtag, case-insensitive match
en-u-co-phonebk-U-ca-buddhist

# well-formed, but the primary language subtag must be a lowercase 2-3 letter
# code (RFC 5646 §2.1.1) — an uppercase primary subtag or a bare 4-letter run
# is rejected by strict parsing while staying well-formed for isValidLanguage
JA
jaja
